Battery management device, battery apparatus, disk array apparatus and battery management method

• US 8,942,075 B2
• Filed: 03/18/2013
• Issued: 01/27/2015
• Est. Priority Date: 03/27/2012
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yoda, Yutaka
• Primary Examiner(s): TRAN, THANG V
• Application Number:
  US13/846,115
• Publication Number:
  US 20130258830A1
• Time in Patent Office: 680 Days
• Field of Search: None
• US Class Current: 369/53.42
• CPC Class Codes: G11B 27/36 Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

Disclosed is a battery management device 1 and the like that maintains each secondary battery (SB) 2 in an appropriate state. The battery management device 1 calculates a degradation state of no smaller than the three SB 2 to be managed separately, selects, as the new power source, one of the SB 2 that have not been selected as a power source among a plurality of the SB 2 as management objects based on the degradation state, selects one of the plurality of the SB 2 that have been selected as the power source based on the degradation state and removing it from the power source, changes a combination of a plurality of the secondary batteries as the power source based on the degradation state, and activates the SB 2 disconnected from the power source by discharging and charging the SB 2.

Claims

1. A battery management device, comprising:

a charging circuit to charge a secondary battery;

a discharging circuit to discharge the secondary battery;

a path switching circuit including a function to switchably connect no smaller than three secondary batteries to be managed with one of the charging circuit and the discharging circuit separately, and a function to connect a plurality of the secondary batteries selected as a power source among the secondary batteries to be managed such that the secondary batteries selected as a power source are in a specific connection state;

an information collection unit to collect at least one of information indicating a charging situation about the secondary battery connected to the charging circuit via the path switching circuit, and information indicating a discharging situation about the secondary battery connected to the discharging circuit via the path switching circuit as battery status information; and

a controller to calculate a degradation state of each of the secondary batteries as a management objects based on the battery status information, and manage each of the secondary batteries as management objects based on the calculated degradation state,

wherein the controller includes;

a function to select the plurality of the secondary batteries as the power source by using the degradation state,

a reorganization function to make one of the secondary batteries not selected as the power source be a new power source as substitute for one of the secondary batteries selected based on the degradation state among the secondary batteries having been selected as the power source,

a refreshing function to activate the secondary battery having been disconnected from the power source by the reorganization function using the discharging circuit and the charging circuit, and

a function to control the path switching circuit according to a prescribed control procedure.

2. The battery management device according to claim 1, wherein

the controller selects a number of the secondary batteries needed as the power source in order of the degradation state from best to worst as the power source.

3. The battery management device according to claim 1, wherein

the controller controls one of a charge operation by the charging circuit and a discharging operation by the discharging circuit so as to adjust a charge amount of the secondary battery selected as the power source to a prescribed first charge amount and a charge amount of the secondary battery not selected as the power source to a prescribed second charge amount lower than the first charge amount, respectively.

4. The battery management device according to claim 1, wherein

the controller monitors a charge amount of each of the secondary batteries selected as the power source and controls, when a sum of the charge amounts becomes below a threshold value, the path switching circuit and the charging circuit so as to charge each of the secondary batteries selected as the power source.

5. The battery management device according to claim 1, wherein

the controller calculates a degradation state of the secondary battery by using the battery status information collected by the information collection unit when the secondary battery is discharged or charged by the refreshing function.

6. The battery management device according to claim 1, wherein,

after electric power of the secondary battery has been used as the power source, the controller connects the secondary battery to the charging circuit via the path switching circuit and charges the secondary battery by the charging circuit, and calculates a degradation state of the secondary battery using the battery status information collected by the information collection unit about this charging.

7. A battery apparatus, comprising:

no smaller than the three secondary batteries; and

the battery management device according to claim 1 to manage the secondary batteries.

8. The battery apparatus according to claim 7, wherein

a number of the secondary batteries not being managed by the battery management device as the power source is less than a number of the secondary batteries being managed by the battery management device as the power source.

9. A disk array apparatus, comprising:

a plurality of hard disks being a storage medium capable of at least one of being read and being written by a computer; and

the battery apparatus according to claim 7 as an auxiliary power supply.

10. A battery management method comprising:

by a computer,

collecting at least one of information indicating a charging situation about a secondary battery to be managed and information indicating a discharging situation about the secondary battery being discharged as battery status information;

calculating a degradation state of the secondary battery to be managed based on the battery status information;

selecting one of a plurality of secondary batteries having not been selected as a power source among no smaller than three secondary batteries to be managed as a new power source based on the degradation state;

selecting one of the plurality of the secondary batteries having been selected as the power source based on the degradation state and disconnecting the selected secondary battery from the power source;

changing a combination of the plurality of the secondary batteries as the power source; and

activating the secondary battery having been disconnected from the power source by discharging and charging the secondary battery.

11. A controller to calculate a degradation state of each of secondary batteries as a management objects, and manage each of the secondary batteries as management objects based on the calculated degradation state,

the controller performs to:

collect at least one of information indicating a charging situation about a secondary battery to be managed and information indicating a discharging situation about the secondary battery being discharged as battery status information;

calculate a degradation state of the secondary batter to be managed based on the battery status information;

select a plurality of the secondary batteries as a power source among no smaller than three secondary batteries to be managed by using the calculated degradation state;

make one of the secondary batteries not selected as the power source be a new power source as substitute for one of the secondary batteries selected based on the degradation state among the secondary batteries having been selected as the power source;

select one of the secondary batteries having been selected as the power source based on the degradation state and disconnect the selected secondary battery from the power source; and

activate the secondary battery having been disconnected from the power source by discharging and charging the secondary battery.